Hunters found to have died after eating infected venison

Two hunters who ate meat from deer known to have chronic wasting disease − or “zombie deer disease” − developed similar neurological conditions and died, raising concerns that it can pass from animals to humans.

Found in deer in northern Colorado and southern Wyoming in the 1990s, chronic wasting disease, or CWD, has been recorded in free-ranging deer, elk and moose in at least 32 states across all parts of the continental U.S., according to the Centers for Disease Control and Prevention.

Deer infected with CWD may be called “zombie deer” because the disease leads to weight loss, lack of coordination, stumbling, listlessness, drooling and lack of fear of people.

Scientists and health officials have been concerned that CWD could jump to humans as mad cow disease did in the United Kingdom in the 1990s. In 2022, scientists in Canada published a study, based on mice research, suggesting a risk of CWD transmission to humans.

Meanwhile, chronic wasting disease continues to spread to more states, with the most recent being Indiana. The disease was detected earlier this month in a male white-tailed deer in the northeastern part of the state, which borders part of Michigan where CWD had previously been detected, according to the Center for Infectious Disease Research and Policy.

The U.S. Geological Survey updated its tracking of chronic wasting disease on Friday to include 33 states by adding Indiana, as well as four Canadian provinces and four other countries: Finland, Norway, Sweden and South Korea.

Researchers at the University of Texas Health Science Center at San Antonio have reported how two hunters who ate venison from a deer population known to have CWD died in 2022 after developing sporadic Creutzfeldt-Jakob disease, or CJD, which is a neurological disease like CWD.

The second man to die, who was 77, suffered “rapid-onset confusion and aggression,” the researchers said, and died within a month despite treatment.

“The patient’s history, including a similar case in his social group, suggests a possible novel animal-to-human transmission of CWD,” they wrote in the case report, presented earlier this month at the annual meeting of the American Academy of Neurology, and published in peer-reviewed journal Neurology.

The researchers did not say where the men lived or hunted. But the highest concentration of CWD-infected deer can be found in Kansas, Nebraska, Wisconsin and Wyoming, according to CDC and US. Geological Survey reports.

Because of the difficulty in distinguishing between the diseases, the researchers said the case does not represent a proven case of transmission. However, “this cluster emphasizes the need for further investigation into the potential risks of consuming CWD-infected deer and its implications for public health,” they wrote.

Also known as chronic wasting disease, “zombie deer disease” is a prion disease, a rare, progressive and fatal neurodegenerative disorder that affects deer, elk, moose and other animals, according to the CDC.

In prion diseases, the abnormal folding of certain “prion proteins” leads to brain damage and other symptoms, according to the CDC. Prion diseases, which usually progress rapidly and are always fatal, can affect humans and animals.

Deer may have an incubation period of up to two years before the onset of symptoms. So, the animals could have the disease but look normal until the onset of symptoms, such as weight loss, notes the U.S. Geological Survey.

Scientists and health officials have been concerned that CWD may jump to humans.